From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755712AbdEESki (ORCPT ); Fri, 5 May 2017 14:40:38 -0400 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:40906 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755040AbdEESk1 (ORCPT ); Fri, 5 May 2017 14:40:27 -0400 X-IronPort-AV: E=Sophos;i="5.38,293,1491264000"; d="scan'208";a="282371802" From: KarimAllah Ahmed To: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: KarimAllah Ahmed , Joerg Roedel , David Woodhouse , David Woodhouse , Anthony Liguori Subject: [PATCH] iommu: intel: Flush the IOTLB to get rid of the initial kdump mappings Date: Fri, 5 May 2017 11:39:59 -0700 Message-Id: <1494009599-20962-1-git-send-email-karahmed@amazon.de> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ever since commit 091d42e43d ("iommu/vt-d: Copy translation tables from old kernel") the kdump kernel copies the IOMMU context tables from the previous kernel. Each device mappings will be destroyed once the driver for the respective device takes over. This unfortunately breaks the workflow of mapping and unmapping a new context to the IOMMU. The mapping function assumes that either: 1) Unmapping did the proper IOMMU flushing and it only ever flush if the IOMMU unit supports caching invalid entries. 2) The system just booted and the initialization code took care of flushing all IOMMU caches. This assumption is not true for the kdump kernel since the context tables have been copied from the previous kernel and translations could have been cached ever since. So make sure to flush the IOTLB as well when we destroy these old copied mappings. Cc: Joerg Roedel Cc: David Woodhouse Cc: David Woodhouse Cc: Anthony Liguori Signed-off-by: KarimAllah Ahmed --- drivers/iommu/intel-iommu.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index d412a31..478130d 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2050,11 +2050,14 @@ static int domain_context_mapping_one(struct dmar_domain *domain, if (context_copied(context)) { u16 did_old = context_domain_id(context); - if (did_old >= 0 && did_old < cap_ndoms(iommu->cap)) + if (did_old >= 0 && did_old < cap_ndoms(iommu->cap)) { iommu->flush.flush_context(iommu, did_old, (((u16)bus) << 8) | devfn, DMA_CCMD_MASK_NOBIT, DMA_CCMD_DEVICE_INVL); + iommu->flush.flush_iotlb(iommu, did_old, 0, 0, + DMA_TLB_DSI_FLUSH); + } } pgd = domain->pgd; -- 2.7.4